SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd850939b165b8c4e37c83f675b1c5c165b91e1bb15937207a7b719d1fcc49e9' 
  AND token = '+NbiTeUlQdUtjEkHlEqQFgiQp6ML7a86gy4+ud8ihb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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