SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66fe4cfa0267e2e9db72e85cd8110996f4411c09b756801f3af1a282ca2a7694' 
  AND token = 'dhXUqwhsQtXvVTPT4GRIT5Vdko/CRZIEM0hQrudDWHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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