SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27d38bc76981eec3e7853276cf103eaf5c7f4bb26b22551bbf338b55f75592fd' 
  AND token = 'uIqsoHGdQuL1mZy6j0NvJR/JBCqixC0g85VMNdgzFqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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