SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad808e608b97065476f2d1aada85cfc6dc1664d40cafe8aae77859718003ffd8' 
  AND token = 'OyboMZ7KFaPqXkE5RdrTmfsvfGre4AZFzheJ0JIctD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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