Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c6d28dd9d38d4cdc776debf7d97f5bd3eb54747c95e0bd9d7686db4146557d26' 
  AND token = 'MRlFgwo4LzmXebv4AADr8tLxHGGlF0OKlQp6tHLsMiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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