SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8323b1a2e5ec30376c5068b256a686f985b7c5924b67eb7ef39f07ce6616fca9' 
  AND token = 'RGoNtTV4KnylB5souCU6tqCazlaFNtKiQAU0wkZgPgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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