SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9580ab04d5ca1cf68acbd8d4dc89f607b330c19a7f818bdf05e2290e6fba18c' 
  AND token = 'xZmOJR1CVLe3Oo8tBdaxVpqKjkkcPMf36DTh85/qcPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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