SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e0f8f5c8b39df3dcffa00201efa7c98c3937ce5bea31dcfec976c5867522a77' 
  AND token = 'CTxelSCY/Ci0ztQXrKIVGmxpfQss7VrdKeFi6LoutBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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