SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '079e3d23b87ec631355efec4d6ab51fd8944fe8afbcf115c4e6fb63b16082b94' 
  AND token = 'vpCR3XCB2nCbiu+0PGydvv723Llh+ShmqhEFZdHip5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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