SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2d19490df0debf887f0074e53a81c9ddc0bcaa3032e33c6d28e9396d65a60d6' 
  AND token = 'c33ECfsMYNDE8nrohUwiiOANVzP1Cz606HKMLEeWOUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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