SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9baa109cc136508415a40fe6ef3cd90173143f457d410b460b152d883dd9c6f0' 
  AND token = 'KcsuL0C8dwdhWiTV7Gi2iwkNZv/Dnmq6rXxDr7sPz9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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