SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '998b58f146e9aa2379412a19fb901760a26234f88db645c0128049da91c444aa' 
  AND token = 'jvAtFvzhe3OSoWCDB7yLe4mwo9m5RHMK1zmspJE2iQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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