SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76a2e3257ea4839d97fae1bd7e35ad5107bd9f57bad57d7a464b759436bbe0a2' 
  AND token = 'h5/9kABUOZOvFMnPwUSV2Q4SYcu1RJhk9iYJtwLWN2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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