SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f94d21cd4fb5f380257f1f3f072732b662787094fd10298f462d183ac8097a3e' 
  AND token = 'OBLW79FucmTXibYHdb+7XT5DIbCTME/mpFHA3FMkRLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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