SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '813190f8e6e3ed1581a6552e9b94a5f069a4af1137216601a89f316bbdf28f22' 
  AND token = 'SpiSHASOzATNQTOg5k08c172UGDNraVsNsQPY4Rao4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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