SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5889e3a7ac3666cc54140d449921cb9d1aa549f10839a267601ebf13a194a02c' 
  AND token = 'rtXpzF/ZQnjTYWLZ/dDMIT5NL0mX9btJTI4ZQh5JITs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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