SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2ae4b7de8eb7b206eb5e0e42643195419e9ddb134a56551609ea4181feb1f62' 
  AND token = 'jmK7SRMOzqDrgVAyR0uTmv2UcEZqJHe+BpEhASCbEGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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