SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b190c970017cae4eb90d46724b52ac5a4cb47ebb27bfcdd2adaf79c57b4367f9' 
  AND token = 'DMNq1xu7LuavueWLVt5K09TyFYM6+GILLpgXz6jsoZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}