SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '433454e823c6f8679022e967db07f454c26c0ea749b9e927d99f04a567160b59' 
  AND token = 'ZpFkX2hM4tHwfWqJkGSuMwtLILvBAgnslv7cKzwIMeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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