SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44c0c8425d3765cd377b160eb8dab1ad606d9ba9b03afa5389f708d21ea22ea2' 
  AND token = '5Lisdj7WEaBjyVfz9U9d/ekYXw8BA+hlvQWYLS5rkR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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