SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '848243c9608bfea1e192a130cdb30bed48eabe3c034768428490cfaf29d622fe' 
  AND token = 'qs7UQyFbm6cACo0xJOedLHB1kdOZkghqvjQYjTu94aY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}