Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'df6591b9ec3004d8a74d433674a9b1d7049ae44b02e7615dd5d90fa10925e4be' 
  AND token = 'T2PMii+A+3eqTUyrLkDhu1/ulMP2/m0Vmjf6hmab6nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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