SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d4656ae697799c66ed687dd9f076af5dc1948e9099d582b93450918bcdff730' 
  AND token = 'YbPr9r0FWF1UZBNokjFX/jVdMhGK6d3Z2JBzT92BpqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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