SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4184081c373c979ec79491adbea339cb2b0864bb5a4164783fd30adb4dccff05' 
  AND token = 'YtuoimFMnsDTToOqFySEuVId3uWIjuf2++cVhYvOoTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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