SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be124d13d15ede9307692e22fd3b007385665ceb05a6619db7254ab77011cbc6' 
  AND token = '2tziUqp1AQsfxLCiXKQt4FIQNJNA2LI5rOSATb49QVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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