SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cf9a1e41fa53b21492efc5c7c40f42a4dd99dba8cb98bde48bf94e05cf06415' 
  AND token = 'GRL6k6MzJ1UMHhunvPuyFpjF3P6KQpz2DKaHpeLhQq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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