SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '30094bc7bf9524d9b871d5d40086d056d4af3ba534ddc4d42d6cc79350d532e2' 
  AND token = 'jPVMf7CJJ8e/5KKtXsfjIg47y9xo61YbMW8ELT32G2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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