SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07228e512cdaa00a39810adab3296855b9350108e7b9d987fa40ac029d9e40bc' 
  AND token = 'cFQAXiBRrWkK+4zb/7YGRFm2JqnMpXCXOxvwoLhxyAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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