SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46c5f41d1a5da298322cd9837dc20f9fe5efe62375ad42515172dae3b4be546b' 
  AND token = 'BPXGYD8opfRQPmPC3pU2XlRXoWAjZ1hXNCykS6PQDAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}