SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a895cb36b5a429cabf5d7fe6780cdedf64a825002266bc25d79107b899502e7d' 
  AND token = 'AMI+EkHHyHaAhZxHEYOcro3NoRWjFMsbWDf4s0CsyyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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