SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cc44c4224ce61941236dbc4d4bd69f3a102559fed60f3f4439398b698a4e12c' 
  AND token = 'o3356PTdPWfg37lFbUJPvu/RES5GwibCkEoWMFr/q9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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