SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1d9651bc1bb1a1157674c8084a74afff79afa38ccd3b752633e59dc1b176ab3' 
  AND token = 'cXVOPGSBCLAAHqI/4SQzOwyujM61CosQB3LCHNaxVA0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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