SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5993849c9d86cccee25c821a7f8af63cbc5ff16b840f0eb4f75bb12091e5f0a' 
  AND token = 'F7V4J7a7h+B7Z10n9dzgYc4BX6R6s1eREHDKkMbAojo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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