SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30ba6b402dd17f95be390092d0c850c820ede4bf77ff795daaefab595d72d51b' 
  AND token = 'joC5LemDcf4aqLQrgpuqrHiZG4z9OUjhZU0qr5RDCRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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