SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc8fafa0f7212db4f4ba4ed0fdfb33dae48d93824875895e8bdc519c6334af44' 
  AND token = 'vQPG5J2aNlWSWkpeeKWfKXh+sGYprkTaLp3UUXEGDtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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