SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9c20e0df149b87ec1496409df6f054116985027176730a127dfa62292c631eed' 
  AND token = 'vu9jRY8tAFHpgppVhzshhyeWB5lr4jSpFDB8Uv5V5Mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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