SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc63c68b664a551a67adbbddd30b3375616c71445baad1c7420755ab137f2418' 
  AND token = 'fCp87JE88QP7GKPyzjSzwyijxWziAfZHazQ/aQl0B00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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