SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c3bc31137fd23b48db18edbdd62f203161aa917317bb8f62494d7c09fe7cafc' 
  AND token = 'ETBjtek/ka3dfYVCfCY0b67Ti/CpPHY99HXEPj2qKGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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