SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3259195d65f2230ffc56244ac3ad318f57c5ab976105111edd73bdce1a6c22f6' 
  AND token = 'PjTlE6hxuNNrrSro0va++73xMi+IgLo4Sd3casBRYhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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