SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a676113251a0fe385f02fee997b66d53ae4dc39f91c908b5a24d1451ed22c1e6' 
  AND token = '/XvwnEP7a4ARbQ2LWF2NNYsf5nXS5R08tiZ2k4Y7xY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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