SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeed975650c186ae63ed3be6d0440b6b654f7518e0fee259f5c559250a7eaa83' 
  AND token = 'vN/yw5hGErn6eIUJ/Rc/3AXvtBa/fgXY0RIV4WtlXCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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