SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc7939f563dc921123d02d75afcbee763b2221f2c6e1aa5fa590f13c6e978ca3' 
  AND token = 'rxbRKY21Eb318umUbae0koUZYf6/cN3yYq1XYyyxZFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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