SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a843a42de85b45d75f796a991c22e0f093162a0452d41034403b29caf1bc9924' 
  AND token = 'MOQRhPOAxvxmGkxJbooTnTwzS03VdfPCf2jOYY9x3NQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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