SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52345f80feeac9c65ed862c664300565002581eb913585885cedda1dfdfdcd24' 
  AND token = 'KFH+/o1P3cI+Z5oP/BBuh7qraKrlTYpLNbUxmGVpaFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}