SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bf95742f307856af6f31ab251938e9697f5ceb561702a344e7ff39845dbf7822' 
  AND token = '9ET3Uh1gCQ5EQnGLTz07BOZXdm1YqeufnQUBIJ3ed7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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