SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2b188a3ade0d88429cd5653bb528d2106db7ea9882949f5cb1bd41889409d2b' 
  AND token = 'acrzG51nR7w2O88O7CrfpPOZgjWZX2XwA6305HaBy7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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