SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3269c24141da89a72c76ba3170884c945c13b833f022a85fd1ddc1b2f3e1717' 
  AND token = 'ICmXxNFgTyzH/w00SN9QyBAB1DsXZp6jSw6kYSNzGnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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