SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c62104dabceccd32e3dd86abaf61ca8ffcfb0868d58da308e86d997a9dec8a1f' 
  AND token = 'jE7YcPXx9T4SnupGdOqGN8HkP4cuwIP7u3lZ7M3JP54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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