SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '392bbc399ba917969035b228645d7c3fce4db2c54e61a08a775c23e165f263e6' 
  AND token = 'M1WxDGtBUqSM+48cbujKWv05W3XQ3PK+knfaJ/OGDxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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