SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16291c1bc31e64f909c3e6eeea42dc741f09ce8249884890ce887af6d34bfeb6' 
  AND token = 'aE7+GZXs2KXUAHHW3QMm5Vs99gqnEq7dY0+8b85rKb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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