SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6cf40f2887dbd784c1381d4de157aade0103db9984eba72d32820a58b0a0817c' 
  AND token = 'j1Q6U5iC63aCColVody9NoomevEYQFtAnmLRr0Sbke4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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