SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6e2761e6e50e97e64567614379c04862d70bf01f100bdf2fb086f89b75d8085' 
  AND token = 'Xwl9c2L/1smZfoERvBeJvg7Bm2OApxr69Sz594kpDXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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