SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e57f3d3296881f5d9cf69bc8b5cb7a3e5fcc24ca4a96af074f02fe28516818eb' 
  AND token = 'OmR7PB3F9cmXDz8D7OYxCNMqat9LlYZ4KnJ/GYK7+Es=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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