SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44b7c0cab156d8cb5f417df9000a631ac1e3743efdf326771f7c06d1b6e057ae' 
  AND token = 'LE58QJc0rgaONmmujX3GS+Frj3pSHNay91xXIAKjv1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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