SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '735915031873d353980a99c18d52ca438b8d9eb2f0e3482f2cff7f1bbf6471fd' 
  AND token = '+HjQj98vvUVHYGIyDAfHwOTKmwLvdUR7ztPAG3dtY7U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}