SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e8c59f18c1661b8bf7782b4458519f4ee2e8984f90a2f585c51e9255f633f02' 
  AND token = 'HH/fqSJhj2oV2R9kqwvdw09T6Gj7igSzLnWVK8OkOO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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