SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9fd93081659a5ca789246c38ef0876e48f12275be5d2cb9b2ae01af62d89462' 
  AND token = 'lq9YvsmHWAC1tbTkPyo361A5/8yH9JSrvogq3bf7qm4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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