SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '587a759066f8d0441afeabdfc24799092c08c62a2072fba56ec7a27a762de6e4' 
  AND token = 'BlcASYiTnxKhPP3wKTWG259bc0SGZMukkPVEvHl/4dY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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