SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f73544df41f8cd3bf60be732069f026a083843cf03f19f019967ae5a1addea3a' 
  AND token = 'j3XQgFkN8eOwrInorWhe4imLvu9ERO/+e4g0+3GEtuc=' 
  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"
    }
  }
}