SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e32bfa4a9a7b1f2d18a589680597662285ff375a03ff5f4152c5908260110815' 
  AND token = '0yLZQABnkTPXKVJeGsbblEuQ4r6zyXpHCrvLgxlahmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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