SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '46c7f9fc19727bb784f0a0a91265f025c048c1f53b4b0e06250d073a5a3adf7e' 
  AND token = 'pdRYSzoKj0R7j+r0KZfUp+x5/XOdX499Ams34nu1VMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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