SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdf1acb2b6df4c8356b35f221c75ccb298f41587f0fefb9fb3255f8762b7689a' 
  AND token = 'jFRg+nkLKdO7QzEI7Pf24OIOw+mVLIsgSNaZmmkoN1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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