SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '556a0c92400563e3c5cc4cff535995d532a26f134cce9b5fbe9e58176142e46b' 
  AND token = 'HmCYlCSxwOdTXZUIwn0TEpsmwf5eNsV+kxwupBw3xSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}