SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f543ddd27cb98e84221da70b0ad25aa88469659c72370f614915a504c24c45b6' 
  AND token = 'QCDsoEqNXf1Nv2vscr2+JpIqokJcF1iIH+YtTTLmsfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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