SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b73b84bddabf1e70723d14efe966070643c0d3870b8e2558b5cb51abffc03536' 
  AND token = 'K9a0xd2sppLS5K2BTwEPHzC2QWcg/UXCBV9eTzdGHG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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