SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cf60c5dd157a657940c57210954a8854431ac12b3e8d3a2d7682967b18a091c' 
  AND token = 'EPWUhSuhzOCi3ILCXajyvwu+K3zKagjAsS9tDo5Hq4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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