SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0a8c554c1fac764c3c7705e59c5a2b248bae4f5a889d09ea547f4fa7e65aead' 
  AND token = 'CpmbQ9vapuQcfPUgSjfGB8LMcoO5UjbAE2niuIWM9ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}