SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e862435cf00803a761163e451620fe97150c7ff85ca7ad56ee3e4f787f5f252' 
  AND token = 'Geisrswkhnu+/IjfOcJNrjW+ZuqZ0wEIt/LGnenbY7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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