SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '724ba03aa8a3cd7944ef81c058d7f2098e15aa663af1a6193e685a901b92c5d2' 
  AND token = 'w29kA5M7eSwpVwCcwvHlVuGEvBrDtt/C1F9ISoJAFf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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