SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4e1f26f200f38a0c72653d9841e0fa9a9165d3b4c96f70148adce3e07dc8749' 
  AND token = 'ucjV49Nf/e/KVb6/iTRDJQDfU5ENHTC6bHQaW8ddzhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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