SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f485f9d1675b15c148ef408cc054ec93fd4b743933a0a787abb9ffeeedbf1f91' 
  AND token = 'sYsMBGftenNT6BfZjmguRSlpoIKvYG+JgpRXFH5ms8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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