SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6311bea6f2e2865cfc77145d104592b6c314d2053598879fb69f9c5f0f8a5014' 
  AND token = '3Lw090YTEZZeMt0nlakvhCA1icL0J4GYZcWYNwHqNTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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