SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3e83dcc334264327903988ae9d13d746ba4d27053a270494a52a9d029bcf9ec' 
  AND token = 'SxI2PYB78E3sZZnQoZtl5yogdWq7Nm8JECCQRl29YZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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