SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfd264fe772c9639bdac9b0353ad1d1cdc39a398b04495abc88e32749ed57783' 
  AND token = 'MQu+1muhx7SKfhmD3wXbLZPpuPP7YqhOx78nI+Bn9sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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