SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a24c4e1821e8fbc41911f34bb32aad4ed005945a98e317e3c0dc33a795af0f48' 
  AND token = 'TDYNM0cUHvDtO0YcphEmdWQ0drzjluSWyVMaBo0Vkyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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