SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'cd52dbd00f7bbc6aafedd4933934950f6c918b4babecb229f8d0e8589398e4cb' 
  AND token = 'MTrr9yICD1s+b7jRlR6YdKVIxadX8Arlj0KQVYKUlqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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