SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48813b16e5c5c855c693f5ad3ba49b29c4fca076c78e3a45fec3a76f516f33ee' 
  AND token = 'nrXc4Wn250l+9z6zwzLRyr1GUKf5feda5Y0B0Sr9A0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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