SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1de948f9a77e4e23d715f852e683f983cea564d89f2a15a92fa879662e9cfee2' 
  AND token = '7dI0l0ady0SGZ2OsZw/zP9Wfor5LLKMkMKen4YaNN2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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