SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ebb53e37a0196eb2632feb4c8a11405fe627cb0785fdfde677f01b19bc59ca2' 
  AND token = 'cMmdms8S8g2HAHgFAGSB3jZHgNpE4lTOqnFCbCxiptg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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