SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3162c601cf85a74bf26a864a35985e617faf1870a1b31b9bf0f190f054deead6' 
  AND token = 'Ys+i7HdvvmUaJpuaMYBD/AZUJyKNGdmzoy5XC+b+MDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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