SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2df7abbed6f1c9ea0680760b55a39f191eec44d58df4ccf20f70928583467d1' 
  AND token = 'g5BU3dWSx1gRXMHIFPOaxjfhWWyDrLmEA+E6RxQ/DW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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