SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd888f72b5aa55507fe3a3489c62923b78fce40c4e5568865b2a0cfa7c84ad2ab' 
  AND token = 'lR9k88GkIybYg4vs+PguQjhJjTKP/kh1vPEMWhjwXGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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