SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e2bac2cc1076478c58a484428d89355ad4b4372b0a26c2f9d55ce0f17f0b67b' 
  AND token = '7gSnm9dBoXlNuGHRYEYulp5380h9pxYqDfzEohxgqNA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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