SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f0278630ab2b814a24201b98216a8d0312402ed411d9271981c5abe5d6aeeff' 
  AND token = 'q82+h+JhxGsaKDKP6g1KRnKJHGIz667JOVyUw9LjV0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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